Kubasik, who had been vice chairman, president and chief operating officer, was to succeed Stevens as CEO of the defense giant Jan. 1. He was asked to resign Friday after an ethics investigation found he had a lengthy relationship with a subordinate.

Stevens said in the conference call (listen to audio) that an employee came forward in late October with concerns about an inappropriate relationship between Kubasik and a subordinate. Lockheed hired an outside firm to do the investigation, which closed with Friday’s emergency board meeting and the firing of Kubasik.

The employee who came forward was not the person involved in the relationship, and the subordinate in the relationship no longer works for the company, Stevens said.

Stevens declined to say who came forward, but said he considered the person to be “quite courageous.”

“As I look at corporate American today and our company, I am very pleased that our employees have enough trust in our leadership and enough confidence in our process that they would step forward with an allegation about the highest level executives in our company, without fear of reprisal and without concern, and know that they would be treated fairly and that their concerns would be given a full expression in an investigation,” he said. “And that’s exactly what’s happened here”

Stevens insisted that the indiscretion was a personal matter for Kubasik and the company will get through this episode without a scratch.

“I don’t believe the company is in crisis. I believe we’re changing course as a result of the observations that were brought forward to us in this ethics matter. We’ve acted cleanly, clearly and decisively, with regard to the action we’ve taken. The very good news is that we have a significant bench strength of executive talent in this company. In my judgment, that’s not accidental,” Stevens said, adding later: “We believe that strategically and operationally and financially, we will not miss a beat.”

Marillyn Hewson, a 29-year Lockheed (NYSE: LMT) veteran, has been tapped to become CEO Jan. 1, when Stevens steps into an executive chairman role. Hewson had been executive vice president of Lockheed’s electronic systems division since January 2010, and was slated to become chief operating officer in January. She was promoted to COO effective Friday.

The company does not immediately plan to fill the COO role, which will be vacant in January.

Stevens said he and Hewson will rework the transition plan as needed.

Stevens grew a bit defensive when a reporter pointed out that he sounded outraged by Kubasik’s actions and the timing of the revelation.